Towards Understanding the Reactivity and Optical Properties of Organosilicon Sulfide Clusters.

We report the extension of the class of organotetrel sulfide clusters with further examples of the still rare silicon-based species, synthesized from RSiCl with R=phenyl (Ph, I), naphthyl (Np, II), and styryl (Sty, III) with Na S. Besides known [(PhSi) S ] (IV), new compounds [(NpSi) S ] (1) and [(StySi) S ] (2) were obtained, the first two of which underwent reactions with [AuCl(PPh )] to form ternary complexes. DFT studies of cluster dimers helped us understand the differences between the habit of {Si S }- and {Sn S }-based compounds. Crystalline 1 showed a pronounced nonlinear optical response, while for intrinsically amorphous 2, the chemical damage threshold seems to inhibit a corresponding observation. Calculations within the independent particle approximation served to rationalize and compare electronic and optical excitations of [(RSi) S ] clusters (R=Ph, Np). The calculations reproduced the measured data and allowed for the interpretation of the main spectroscopic features.